Apparatus for discharging of molten metal from electrolysis furnaces

ABSTRACT

AN APPARATUS FOR DISCHARGING OF MOLTEN METAL FROM ELECTROLYSIS FURNACES WHEREIN THE DISCHARGING IS EFFECTED BY SUCKING THE METAL FROM THE FURNACE BATH INTO A CRUCIBLE, COMPRISING, A GANTRY STRUCTURE HAVING A PAIR OF INTERCONNECTED LEGS WHICH SPAN A ROW OF THE FURNACES AND ARE ADAPTED TO RUN ALONG EITHER SIDE THEREOF AND TRANSVERSELY BEYOND THE ENDS THEREOF, AT LEAST ONE OF THE GANTRY LEGS IS PROVIDED WITH AN OBLIQUE GUIED STRUCTURE EXTENDING OUTWARDLY AND INWARDLY RELATIVE TO THE OTHER LEG, SUCH GUIDE STRUCTURE BEING PORVIDED WITH CRUCIBLE SUPPORTING MEANS ADAPTED TO MOVE THE CRUCIBLE ALONG THE LENGTH OF THE GUIDE STRUCTURE.

G. HEGGSTAD ETAL 3,561,206 APPARATUS FOR DISCHARGING OF MOLTEN METAL FROM ELECTROLYSIS FURNACES Filed Jan. 24. 1968 @Sheets-sheet 1 March 2, 1971 MDM wmff 55m/Ww Ms m 5 /Ewr t WNW MN 04M um f dm March 2, 1971 G, HEGGSTAD ETAL 3,567,206

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March 2, 1971` G HEGGSTAD ETAL 3,561,206

" APPARATUS FOR DISCHARGING 0F MOLTEN METAL FROM ELEcTRoLYsIs FURNACES Filed Jan. 24, 1968 6 Sheets-Sheet 5 0M Wm M Jij am fw Dm m MMM pw m U FIIIIILIIIIIL March 2, 1971 Filed Jam. 24. 1968 G. HEGGSTAD ETAL APPARATUS FOR DISCHARGING OF MOLTEN METAL FROM ELECTROLYSIS FURNACES 6 Sheets-Sheet 6 600m/N0 #66657210 Jo//AA/ /V//fam/ SMOM United States Patent O Int. C1. F27d 3/06 U.S. Cl. 266-38 2 Claims ABSTRACT 0F THE DISCLOSURE An apparatus for discharging of molten metal from electrolysis furnaces wherein the discharging is effected by sucking the metal from the furnace bath into a crucible, comprising, a gantry structure having a pair of interconnected legs which span a row of the furnaces and are adapted to run along either side thereof and transversely beyond the ends thereof, at least one of the gantry legs is provided with an oblique guide structure extending outwardly and inwardly relative to the other leg, such guide structure being provided with crucible supporting means adapted to move the Crucible along the length of the guide structure.

The present invention relates to an apparatus for discharging of molten metal from electrolysis furnaces, in particular furnaces for electrolytical production of aluminium, but in general furnaces for the production of metal which is to be discharged from the furnaces in a molten state.

For the purpose of performing such discharging of electrolysis furnaces, it is known to suck the metal from the furnace bath into a crucible or pot which may be suspended in a travelling crane or which is carried by a paticular carriage which may be moved along a row of furnaces. In both cases, the discharging has involved a laborious con# trol of the crane equipment or the carriage, both along the furnace row and when passing from one side of a furnace row to the other, and from one furnace row to another in the same hall.

The object of the present invention is an apparatus which is adapted to facilitate all operations, both through the structural design of the apparatus and by being adapted for remote control of all operations.

According to the invention, this purpose is achieved whereby the pot or crucible, into which the metal is to be sucked from the furnace bath, `is suspended in one leg of a framework Which is formed as a gantry extending transversely of the greater length dimension of a furnace and adapted to be moved longitudinally along the length of the furnace, and transversely to the same beyond the end of a furnace, such crucible being movably mounted in an oblique guide in the gantry leg, which guide extends upwardly and outwardly, transversely to the greater length dimension of the furnace. In this manner, the crucible may easily and positively be positioned in the correct position relatively to the furnace bath to be discharged, and to be displaced from one furnace to the next in one and the same row of furnaces and thereupon from one furnace to the next in an adjacent row of furnaces.

For the purpose of increasing the capacity of the gantry,

rice

i.e. the amount of metal which may be sucked from the furnaces prior to the discharge of the crucible, or for the purpose of performing the discharging of the crucible while maintaining the suction, it is convenient to arrange one Crucible in each of the gantry legs, to the effect that one furnace may be discharged from one side of the row of furnaces at the same time as the crucible in the other leg is discharged into a transport pot or the like.

In order to perform the discharge of the furnace bath, it is necessary to blow a hole in the furnace crust and to introduce a suction conduit downwardly through the hole. Up till now, this has been performed by hand or with suitable equipment, all requiring manual activity, independent of the discharge proper. In the apparatus according to the invention, this manual activity is avoided as the gantry may be provided with equipment enabling the suction conduit leading from the Crucible into the furnace bath to be so formed as simultaneously to serve as a reciprocatory pricker, or the gantry may be provided with a particular hammer or pricker device associated with the suction conduit in such a manner that the latter may be carried exactly into the crust opening provided by the device, before any growing-in of the same.

With the suction conduit secured to the crucible, and the crucible so arranged that it is movable along an oblique path in the gantry leg, the suction conduit is not only posi tively guided downwardly into the furnace bath, but the distance between the furnace bath and the crucible during the discharge will be the shortest possible, at the same time that the crucible with the associated conduit will be positioned at a safe distance from the furnace bath when out of discharging operation, such as when the gantry is moved from one furnace to the next, or during discharge of the crucible. Such discharge may be effected by providing the gantry with pressure equipment, such as by air pressure from the crucible into a transport pot or the like.

For the purpose of facilitating the control of the arrangement, including the various functions of the same, it is convenient to provide the portal with primary machinery, both for the various movements of the apparatus as a whole, and for the performances of the equipment bringing the metal into, and aagin out of the crucible. Accordingly, the primary machinery may comprise an electric motor connected to electrical supply lines extending along the length of the furnace hall or, preferably, a combustion engine, driving one or more electric generators feeding particular electric motors serving the various functions, and/or for the operation of pneumatic or hydraulic pumps for the operation of corresponding partie ular equipment serving the various functions. Through such a concentration of the operational equipment, the Control of the apparatus is highly facilitated, the gantry being, by way of example, provided with a program controlled control equipment controlling all the functions, to the effect that the operation of the apparatus, along one or more rows of furnaces may be established in beforehand and then automatically performed, without the necessity of an operator who would only be subjected to heat and gases from the furnaces.

In the accompanying drawing, an example is shown of the manner in which the invention may be brought into performance.

FIG. la is a left half view of the apparatus, as seen in a direction along the length of a furnace.

FIG. 1b is a right half view of the apparatus shown in FIG. 1a.

FIG. 2a is a view as seen in a left half direction transverse to that of FIGS. la and lb.

FIG. 2b is a right half view of that shown in FIG. 2a.

FIGS. 3a and 3b are views of the apparatus, as seen from above, each of the two halves of the figure showing merely such parts which are not clearly apparent from the other.

In the drawings, 1 is the furnace proper, having anode bars 2 and a furnace container 3, the crust of which is indicated at 4 and the surface of the molten metal is indicated at 5. The hall oor is indicated at 6, and is provided with lengthwise extending, insulated rails 7 which, in conventional manner, are sectioned into comparatively short, mutually insulated lengths. The rails 7 are adapted for the running of a gantry structure 8, which extends across the furnace 1 and in each of the two portal legs is provided having running wheels 9 and a drive motor 10.

Further, each of the two gantry legs is provided with running wheels 11 and a motor 12, the wheels 11 having a travelling direction transverse to the longitudinal direction of the rails 7, on rails arranged beyond the ends of the rows of furnaces, but not shown in the drawings. The wheels 11 are shown in a raised position in the gantry 8, but may be lowered into engagement with their rails by means of jacks 13. Through continued lowering of the wheels 11 relatively to the gantry, the latter is raised relatively to the hall tloor 6, to the effect that the running wheels 9 are raised out of engagement with their rails 7.

Further, each gantry leg as seen in FIGS. la and lb is provided with an oblique set of guide rails 14 which extend upwardly and outwardly in a direction transversely to the longitudinal direction of the furnace and adapted to receive a carriage 1S which is movable along the guides 14 on wheels 16 by means of a motor 17 and a screw threaded rod 18. By means of a three-point suspension, a crucible 19 is supported in the carriage 15, one of the suspension devices being provided with a weighing implement 20. A suction conduit 21 is secured to the crucible 19 and extends obliquely downwardly and inwardly transverse to the longitudinal direction of the furnace. Further, the crucible 19 is adapted to receive a suction conduit 22 for the discharging of the crucible. The conduit 22 is shown to the right in FIG. 1b in dismounted condition, and to the left in FIG. la mounted on the crucible 19.

Each gantry leg is also provided with a crust breaker device 23, in the form of a sledge or a bar, which is operated by means of a jack 24. In FIG. la, there is also indicated a device 25 for the supply of a light ow of air under pressure outwardly through the suction conduit 21 for the purpose of preventing the introduction of crust lumps and/or metal lumps into the pipe 21 when the same is lowered into the furnace bath 3. As shown in FIG. 1a, one of the gantry legs is provided with a diesel engine 26 for the operation of a hydraulic pump 27 for the operation of the various motors and jacks referred to above, and pneumatic pump 28 providing suction and pressure to the crucibles 19.

Further, the gantry is provided with a contact 29 (FIG. lb) adapted to cooperate with a contact 30 (FIG. 1a) provided on the furnace, and also contacts 31 (FIGS. 2a and 2b) adapted to cooperate lwith corresponding contacts (not shown) in the furnace hall, all for the positioning of the gantry in correct positions relatively to the furnaces and to the longitudinal rails 7, respectively.

The apparatus operates in the following manner:

The initial position of the gantry is at one end of a row of furnaces, with both crucibles 19 in their raised position. Upon starting of the diesel engine 26 and introduction of the program which the apparatus is to follow along the furance row, the gantry is started, and stops when the contacts 29 and 30 engage each other,

whereby the gantry is stopped in correct position relatively to the furnace which, according to the program, is selected for discharging. Under the control of the program implement, the crust breaker 23 in one gantry leg is started through energisation of its jack 24. When the breaker is penetrating the crust 4, the motor 17 is started, to the effect that the crucible 19, with the suction conduit 22 being moved downwardly along its guide 14, so that the end of the conduit 21 is introduced into the opening formed by the crust breaker 23 in the crust `4, until the end of the conduit 21 is penetrating the surface 5 of the molten metal in the furnace pot 3. Simultaneously, and as mentioned above, a light flow of air under pressure is passed outwardly through the conduit 21 for the purpose of preventing a blocking of the conduit.

By means of the pump 27, the crucible 19 is subjected to a depression, to the effect that metal is sucked from the furnace pot 3 upwardly into the crucible, at the same time as the weighing implement 20 indicates the amount of metal sucked into the crucible, until the furnace bath is discharged to the extent desired. The motor 17 is then restarted, in the opposite direction, and the crucible 19 is moved upwardly along the guides 14, whereupon the gantry is moved on to the next furnace which is to be discharged.

In this manner, the operation is continued, until the crucible has received the desired amount of metal, however without being excessively full, whereupon the crucible of the other gantry leg is switched on and operates in the manner described in relation to the first crucible.

Discharging of the crucible may `be performed while the second crucible is performing the discharging of the furnace, baths, or when both crucibles are full. For this purpose, the discharge conduit 22 is manually mounted on the crucible, as shown in FIG. la. By means of the pump 27, the surface of the metal in the crucible is subjected to a pressure, and the metal is pressed over into a transport pot which, conveniently is mounted on a carriage, not shown. Upon terminated discharging of the crucible 19, the conduit 22 is dismounteds and the crucible is once more ready for a new operational cycle.

When one furnace row has been served, and the gantry is to be transferred to another furnace row, it is moved beyond the end of the row of furnaces served, the jacks 13 are energised so that the wheels 11 are brought into engagement with their transversely directed rails and the gantry is raised so that the wheels 9 are disengaged from their longitudinally extending rails 7. Through energisation of the motors 10, the gantry is run in the transverse direction, until the contact 31 engages the corresponding contact in the furnace hall, and the gantry is in correct position relatively to the longitudinal rails 7 corresponding to the row of furnaces now to be served. Thereupon the cycle of operations already described is repeated.

In the embodiment of the apparatus according to the invention which is described above, the crucible 19 is shown in a permanent, but movable relation to its guides 14 in the gantry leg, and may be in a size permissible by the dimensions of the gantry, However, the crucibles may also be made so that they may be lifted out of their guides, for instance by means of a transport carriage, when to be discharged. In the embodiment shown, the suction conduit 21 is secured to the crucible 19, and the crust breaker is made as an independent device. However, it is also possible to combine the devices, the suction conduit 21 being made in the form of a crust breaking tool and so arranged as to be longitudinally movable relatively to the crucible during the crust breaking.

It is indicated above that the gantry is provided with means for program control of the operational cycle. Such means, and the type of program control do not form any part of the present invention, and may be formed in a variety of ways. However, the apparatus may also be adapted for manual control, and for operation in cooperating with other equipment for the operation of the furnaces.

We claim:

1. An apparatus for discharging of molten metal from electrolysis furnaces, wherein the discharging is effected by sucking the metal from the furnace bath into a crucible comprising, a gantry structure having two interconnected legs, said gantry legs spanning a row of the electrolysis furnaces and being adapted to be run along runways extending to either side of said row, and also to be run along runways extending transversely to said rows beyond the ends of the rows, at least one of said gantry legs being provided with an oblique guide structure extending downwardly and inwardly relatively to the other leg of said gantry structure, said guide structure being provided with Crucible supporting means adapted to move the crucible along the length of said guide structure.

2. An apparatus as claimed in claim 1 wherein said gantry is provided with primary machinery for the movements of said gantry, as well as for the operation of the discharge means.

References Cited UNITED STATES PATENTS 850,757 4/1907 Hutchings 212-15X 2,366,574 l/l945 Taylor 2l2-15X 2,549,790 4/1951 Finkeldey et al. 266-38 3,383,294 5/1968 Wood 204-245X 3,389,809 6/1968 Wilson 212-13X J. SPENCER OVERHOLSER, Primary Examiner J. S. BROWN, Assistant Examiner U.S. Cl. X.R. 

